UK Ideal Weight Calculator
Enter your details to estimate a healthy weight range (BMI) and popular ideal body weight targets in kg, stone, and lb.
What is an ideal weight?
An “ideal weight” is best treated as a target zone, not one exact number. In the UK, most people start with BMI-based guidance from the NHS, then add practical context such as body composition, age, health conditions, and activity level. This page combines both approaches:
- Healthy BMI range: a broad evidence-based range for adults.
- Ideal body weight formulas: traditional estimates (Devine, Robinson, Miller, Hamwi).
Using both gives a more realistic view than relying on a single calculation.
How this UK ideal weight calculator works
1) Height conversion
You can enter height in centimetres or feet and inches. The calculator converts everything to metric internally for consistency.
2) Healthy weight range from BMI
It calculates your weight range at BMI 18.5 to 24.9 using your height. This is commonly used for adult screening and population-level guidance.
3) Formula-based ideal weight targets
The tool estimates ideal body weight using four established formulas, then shows:
- Each formula result
- An average target
- A formula range (minimum to maximum estimate)
Why show kg, stone, and pounds?
In the UK, people often discuss body weight in stone and pounds, while clinical settings usually use kilograms. Showing all three helps you compare health guidance with real-world goals, gym programmes, and medical appointments.
Important limitations to understand
No ideal weight calculator can directly measure health. Two people at the same height and weight can have very different health profiles. Results can be influenced by:
- Muscle mass and body fat distribution
- Ethnicity and frame size
- Medication, hormonal changes, and menopause
- Pregnancy or post-partum status
- Long-term conditions (for example thyroid, kidney, or cardiac disease)
So treat this as a decision-support tool, not a diagnosis.
Using your result in a practical way
If your weight is above range
Start with small, sustainable changes: regular meals, higher-protein choices, more fibre, and gradual activity progression. A modest loss of 5-10% body weight can improve blood pressure, glucose control, and energy.
If your weight is below range
Focus on nutrient-dense calories and resistance training where appropriate. Unintentional low weight should be discussed with a GP to rule out medical causes.
If you are within range
Great—maintain momentum with sleep quality, strength training, step count, and routine health checks rather than chasing a smaller number unnecessarily.
Frequently asked questions
Is BMI accurate for everyone?
Not perfectly. BMI is useful for screening, but it can overestimate risk in very muscular people and underestimate risk in those with low muscle mass but high visceral fat.
What is a healthy waist target?
Waist measurement can add useful context. In adults, a larger waist is linked with higher cardiometabolic risk even when BMI is “normal.”
Should I use one exact ideal weight?
No. A realistic target is usually a range that supports good energy, strong daily function, and manageable habits.
Final note
This ideal weight calculator UK tool gives a strong starting point. If you have medical conditions, rapid weight change, eating concerns, or uncertainty about your target, speak with your GP, a registered dietitian, or a qualified clinician for personalised advice.